1. Field of the Invention
The present invention relates to a display device applied to a signboard attached to a ceiling, a wall surface or the like of a building.
In particular, the present invention relates to a display device for causing a plurality of light sources arranged on a display surface thereof to emit light so as to display, at night, still images, character data, video images or the like.
2. Description of the Prior Art
Conventional methods for displaying a large size image at the top of a building or on a wall surface thereof include posting a color film or a color poster on a flat surface so as to illuminate the flat surface on a front side thereof with a lamp. This method permits viewers to recognize the illuminated color film or color poster at night.
Conventional methods for displaying a large size image at the top of a building or on a wall surface thereof also include illuminating the flat surface on which the color film or the color poster is posted on a backside of the flat surface with a light source disposed thereon, and causing neon tubes which are deformed to form a predetermined shape to emit light at night.
Moreover, a conventional method for displaying arbitrary still images or video images as large size images with a large-sized image display panel is well-known. On the large-sized image display panel, light emitting elements, such as discharge tubes, light bulbs, light-emitting diodes or other similar emitting devices, are so arranged to form a matrix shape.
Furthermore, a conventional method for displaying still images as large side images on a display device such as Q board is familiar. On the display surface of the display device, a plurality of cuboidal display elements whose surfaces are applied to red, blue, green, white and so on, respectively, are mounted so as to rotate by magnetic force, thereby displaying the still images.
Each of the display device with the flat surface on which the poster or the like is posted and the display device with the neon tubes can be designed at relatively low cost, whereas it has a disadvantage such that the displayed presentation must be fixed. In particular, in cases where no lighting devices are provided, it is impossible to visibly recognize the displayed presentation on the posting display device at night.
In addition, the automatic large-sized image display panel allows freedom of presentation to be increased because of dealing with video images in addition to the still images.
The large-sized image display device, however, has a disadvantage such that it is costly and requires much power consumption because, in order to form an image which can be visible in the daytime, the brightness of the image must exceed that caused by a reflection of outside light represented by sunlight and so on.
Furthermore, the magnetic rotating type of display device has low power consumption, but it cannot display animations, video images and so on, which have fast frame speeds, respectively.
The present invention is directed to overcome the foregoing disadvantages. Accordingly, it is an object of the present invention to provide a display device which is capable of taking advantage of a posting display device and and automatic light emitting display device so as to serve as a posting signboard making use of sunlight in the daytime and as an automatic light emitting display device for displaying images at night, thereby improving expressive power of the display device with its cost low.
According to one aspect of the present invention, there is provided a display device comprising a display surface portion including a light emitting area on which a plurality of light emitting devices are arranged, and a nonluminous area formed on spaces among the arranged light emitting devices on the display surface portion, the nonluminous area being formed with a nonluminous image, the nonluminous image being displayed on the nonluminous area in color; and emission means for selectively causing at least one of the light emitting elements to emit light so as to display an image on the display surface portion.
According to this aspect of the present invention, it is possible to visibly recognize the nonluminous image on the display surface portion in the daytime, and, at night, by causing at least one of the light emitting elements to emit light, the image formed by the selectively emitted light of at least one of the light emitting elements.
This aspect of the present invention has an arrangement of comprising a device body to which the light emitting elements are disposed, wherein the display surface portion includes a front panel having a plurality of through holes and a transparent seat mounted on the front panel, the through holes corresponding to the light emitting elements, the nonluminous area being formed on the transparent seat, the front panel being attached to the device body so that the through holes are opposite to the light emitting elements, respectively.
According to the preferred embodiment of this aspect, it is possible to prevent light leaking from the light emitting elements at night, thereby improving a display effect when the outside light is weak. The replacement of the front panel causes the displayed nonluminous image to be easily changed into new different nonluminous image.
In a preferred embodiment of this aspect, the nonluminous image on the nonluminous area of the transparent seat is formed with transparent coloring matter.
According to this preferred embodiment of this aspect, it is possible to easily change the displayed nonluminous image into a new different nonluminous image by removing the seat to post a new seat on which the new different nonluminous image is formed.
In the preferred embodiment of this aspect, the device body includes supporting members for fixedly supporting the light emitting elements, the nonluminous area being formed on the front panel, the front panel being attached to the supporting members of the device body so that the through holes are opposite to the light emitting elements, respectively.
Accordingly to the preferred embodiment of this aspect, because the supporting members support simultaneously the light emitting elements and the front panel, accurately setting of the attachment position of the light emitting elements to the support members and the attachment position of the front panel permits the light emitting elements and the through holes to be located accurately opposite to each other.
In the preferred embodiment of this aspect, each of the light emitting elements is a light emitting diode.
According to the preferred embodiment of this aspect, because the light emitting diode has a relatively compact-sized light emitting element, it is possible to minimize the light emitting area, as compared with using discharge bulb or a light bulb, by using a relatively compact light emitting diode, thereby improving the visibility of the nonluminous image.